Use of latent pigments for high-remanence dyeing, composition containing the said pigments and processes using them

ABSTRACT

The invention relates to the use, for dyeing keratin fibres, of at least one latent pigment, which is soluble in a medium that is suitable for dyeing, and which can be chemically, thermally or photochemically converted in the fibres into water-insoluble pigments, of formula A(B) x  
         with A representing the chromophoric radical of dyes,   and B representing a hydrogen atom or a group of formula (II)       

     
       
         
         
             
             
         
       
         
         
           
             with Z representing a cationic water-solubilizing group Z +  or a polyethylene glycol residue, Y representing a hetero atom, F and F′ representing a linear or branched C 1 -C 14  alkylene chain, which may contain hetero atoms and may be substituted with one or more hydroxyl, amino or halogen groups. 
           
         
       
    
     The invention also relates to processes for dyeing keratin fibres using latent pigments, to particular compositions containing them and to multi-compartment dyeing devices or “kits”.

The invention relates to the use of latent pigments for dyeing keratinfibres, preferably human keratin fibres and in particular the hair, toprocesses for dyeing human keratin fibres using these compounds and toparticular compositions containing these compounds.

It is known practice to dye human keratin fibres, and in particular thehair, with dye compositions containing oxidation dye precursors, whichare generally known as oxidation bases. These oxidation bases arecolourless or weakly coloured compounds, which, when combined withoxidizing products, give rise to coloured compounds by a process ofoxidative condensation.

It is also known that the shades obtained with these oxidation bases maybe varied by combining them with couplers or coloration modifiers. Thevariety of molecules used as oxidation bases and couplers allows a widerange of colours to be obtained.

This oxidation dyeing process consists in applying to the keratin fibresoxidation bases or a mixture of oxidation bases and couplers with anoxidizing agent, for example aqueous hydrogen peroxide solution, leavingthe fibres to stand and then rinsing them. The colorations resultingtherefrom are permanent, strong and resistant to external agents,especially to light, bad weather, washing, perspiration and rubbing.

Although these colorations produce strong, fast glints, the use of anoxidizing agent such as aqueous hydrogen peroxide solution, which isoften in the presence of an alkaline agent, results in degradation ofthe keratin fibres.

There is thus a real need to find chromatic dyes which can dye humankeratin fibres as strongly as oxidation dyes, which are just aslight-stable as oxidation dyes, and which are also resistant to badweather, washing and perspiration. There is also a real need to finddyes that can produce rises in colour comparable to those obtained withoxidation dye precursors. Furthermore, the Applicant has sought toobtain dyes with a good level of harmlessness that do not degradekeratin fibres.

The inventors have discovered that the use of latent pigments allowskeratin fibres to be dyed strongly and in a very long-lasting manner,without, however, degrading them. These surprising performance qualitiesare obtained using latent pigments, which are molecules that are solublein dye formulations, and which produce molecules that are very sparinglysoluble or even insoluble in water when they are in keratin fibres.

Latent pigments are known substances. They have been described in patentapplication WO 98/32802, especially in the field of paints, inks andplastics.

A latent pigment is a compound that is insoluble, or only very sparinglysoluble, in water (for instance a pigment), which has been converted soas to make it soluble in an aqueous formulation. Thus, the aqueous dyeformulation containing the latent pigment is applied to the keratinfibres. After diffusing this soluble compound in the fibres, a“breaking” reaction is performed, leading to the formation of asubstantially insoluble molecule, for the final pigment. These“breaking” reactions are known methods. They are thermal, chemical orphotochemical reactions on the latent pigment, which is soluble. Thesereactions result in the breaking of the bond between the chromophoricradical and the solubilizing group(s). This breaking reaction may beconsidered as a reaction to regenerate a sparingly soluble originalcompound, and may be performed inside the keratin fibre.

One subject of the present invention is the use for dyeing keratinfibres, in particular human keratin fibres and more particularly thehair, of latent pigments. The invention also relates to a cosmeticcomposition comprising at least one latent pigment. Another subject ofthe invention is processes for dyeing keratin fibres using latentpigments, and also multi-compartment dyeing devices or “kits”.

Other characteristics, aspects, subjects and advantages of the inventionthat are featured in the description below will allow the invention tobe defined more clearly.

In accordance with the invention, use is made, for dyeing keratinfibres, in particular human keratin fibres and more particularly thehair, of latent pigments, which are soluble in a medium that is suitablefor dyeing, and which can be chemically, thermally or photochemicallyconverted in the fibres into water-insoluble pigments.

The latent pigment used according to the present invention is preferablyrepresented by formula (I)A(B)_(x)  (I)in which

-   -   x represents an integer ranging from 1 to 8,    -   A represents the chromophoric radical of dyes comprising a        hetero atom chosen from N, O and S, and        -   when x=1, B represents a group of formula (II),        -   when x is greater than 1, B denotes a hydrogen atom or a            group of formula (II),    -   B denoting at least once a group of formula (II),    -   the group of formula (II) corresponds to

-   -   in which    -   Z represents a cationic water-solubilizing group Z⁺ or a        polyethylene glycol residue,    -   Y represents a hetero atom chosen from the group formed by N, O        and S, Y preferably being O,    -   F and F′ represent, independently of each other, a linear or        branched C₁-C₁₄ alkylene chain, which may contain hetero atoms        and may be substituted with one or more hydroxyl, amino or        halogen groups, n, m and m′ denote, independently of each other,        0 or 1,    -   B being linked to a hetero atom chosen from the group N, O and S        of the chromophore A.

Z⁺ is preferably an aliphatic group, an aromatic group, a saturated orunsaturated carbocyclic group or a heterocyclic group and bears at leastone quaternized nitrogen atom.

Preferably, the chromophore A is the radical of dyes such as perylene,quinacridone, dioxazine, isoindoline, indigo, bisisoindoline,phthalocyanin, pyrrolopyrrole, quinophthalone, azo, anthraquinone,indanthrone, isoindolinone, naphthoquinone, benzoquinone andazo-methine.

The term “halogen” means an element chosen from fluorine, chlorine,bromine and iodine.

More particularly, the chromophoric radical A is chosen from:

-   -   the perylene derivatives of formula (III) or (IV)

-   -   in which    -   D represents a hydrogen atom, a halogen atom, a linear or        branched C₁-C₂₄ and preferably C₁-C₆ alkyl group, or a phenyl,        benzyl or phenethyl group optionally substituted with a C₁-C₆        alkyl group, or a group of formula B,    -   E represents a hydrogen atom, a halogen atom, a linear or        branched C₁-C₂₄ and preferably C₁-C₆ alkyl group, a C₁-C₆ alkoxy        group or a phenyl group,    -   the quinacridones of formula (V)

-   -   in which    -   R₁ and R₂, independently of each other, represent a hydrogen        atom, a halogen atom, a linear or branched C₁-C₂₄ and preferably        C₁-C₆ alkyl group, a C₁-C₆ alkoxy group or a phenyl group,    -   the dioxazines of formula (VI) or (VII)

-   -   in which    -   R₃ represents a hydrogen atom, a halogen atom or a linear or        branched C₁-C₂₄ and preferably C₁-C₆ alkyl group,    -   R₄ and R₅ each represent a C₁-C₄ alkyl group,    -   the isoindolines of formula (VIII), (IX) or (X)

-   -   in which    -   R₆ is represented by formula (XI),    -   R₇ represents a hydrogen atom, a linear or branched C₁-C₂₄ and        preferably C₁-C₆ alkyl group, a benzyl group or a group of        formula (XII),    -   R₈ represents a hydrogen atom, a group of formula (XI) or the        group B,

-   -   R₉, R₁₀, R₁₁ and R₁₂, independently of each other, represent a        hydrogen atom, a halogen atom, a linear or branched C₁-C₂₄ and        preferably C₁-C₆ alkyl group, a C₁-C₆ alkoxy group or a        trifluoromethyl group,    -   the indigo derivatives of formula (XIII)

-   -   in which    -   R₁₃ represents a hydrogen atom, a halogen atom, a linear or        branched C₁-C₆ alkyl group, a C₁-C₆ alkoxy group or a nitrile        group,    -   the bisisoindolinone derivatives of formula (XIV) or (XV)

-   -   in which    -   R₁₄ and R₁₅, independently of each other, represent a hydrogen        atom, a halogen atom or a linear or branched C₁-C₄ alkyl group,    -   the anthraquinoid derivatives of formula (XVI) or (XVII)

-   -   in which R₁₆ represents a hydrogen atom or a halogen atom,    -   the phthalocyanin derivatives of formula (XVIII)

-   -   in which    -   M represents H₂, a divalent metal chosen from copper, magnesium,        iron, zinc, aluminium, manganese, calcium and barium, or a        divalent metallic group such as MnO or TiO,    -   T₁ represents a group —CHR₁₈—, —CO— or —SO₂—,    -   R₁₇ represents a hydrogen atom, a linear or branched C₁-C₆ alkyl        group, a group —N(B)R₁₈, —N(B)₂, —NHCOR₁₉ or —COR₁₉, or a group        of formula

-   -   R₁₈ represents a hydrogen atom or a linear or branched C₁-C₆        alkyl group,    -   R₁₉ represents a linear or branched C₁-C₆ alkyl group,    -   R₂₀ represents a hydrogen atom, a halogen atom, a linear or        branched C₁-C₆ alkyl group or a C₁-C₆ alkoxy group,    -   z represents 0 or 1,    -   y represents an integer from 1 to 8,    -   the pyrrolopyrrole derivatives of formula (XIX) or (XX)

-   -   in which G and L, independently of each other, may have the        meaning:

-   -   R₂₁ and R₂₂, independently of each other, represent a hydrogen        atom, a halogen atom, a linear or branched C₁-C₂₄ and preferably        C₁-C₆ alkyl group, a C₁-C₆ alkoxy group, a C₁-C₁₈ alkylthio        group, a C₁-C₁₋₈ alkylamino group, a cyano, nitro, phenyl,        trifluoromethyl or C₅-C₆ cycloalkyl group, a group —C═N— (C₁-C₂₄        and preferably C₁-C₆ alkyl),    -   a group of formula

-   -   an imidazolyl, pyrazolyl, triazolyl, piperazinyl, pyrrolyl,        oxazolyl, benzoxazolyl, benzothiazolyl, benzimidazolyl,        morpholinyl, piperidyl or pyrrolidinyl radical,    -   T₂ represents —CH₂—, —CH(CH₃)—, —C(CH₃)₂—, —CH═N—, —N═N—, —O—,        —S—, —SO—, —SO₂— or —NHR₂₇,    -   R₂₃ and R₂₄, independently of each other, represent a hydrogen        atom, a halogen, a linear or branched C₁-C₆ alkyl group, a C₁-C₆        alkoxy group or —CN,    -   R₂₅ and R₂₆, independently of each other, represent a hydrogen        atom, a halogen atom or a linear or branched C₁-C₆ alkyl group,    -   R₂₇ represents a hydrogen atom or a linear or branched C₁-C₆        alkyl group,    -   the quinophthalone derivatives of formula (XXI) or (XXII)

-   -   in which    -   R₂₈ represents a hydrogen atom or a group OB,    -   R₂₉, R₃₀, R₃₁ and R₃₂, independently of each other, represent a        hydrogen atom, a halogen atom, a linear or branched        COO(C₁-C₆)alkyl group or a linear or branched CONH(C₁-C₆)alkyl        group,    -   the azo compounds of formulae (XXIII) to (XXVIII)

-   -   in which    -   R₃₃, R₃₄, R₃₅, R₃₆, R₃₇, R₃₈ and R₄₀, independently of each        other, each represent a hydrogen atom, a halogen atom, a linear        or branched C₁-C₆ alkyl group, a C₁-C₆ alkoxy group, a nitro or        acetyl group or an SO₂NH(C₁-C₆)alkyl group,    -   R₃₉ represents a hydrogen atom, a halogen atom, a linear or        branched C₁-C₆ alkyl group or a C₁-C₆ alkoxy group,    -   the anthraquinone derivatives of formula (XXIX) or (XXX)

-   -   in which    -   R₄, and R₄₂, independently of each other, represent a hydrogen        atom, a halogen atom, a linear or branched C₁-C₁₂ alkyl group, a        C₁-C₆ alkoxy group or a C₆-C₁₂ aryl group, which is        unsubstituted or substituted with one or more halogen atoms, one        or more linear or branched C₁-C₆ alkyl, nitro or acetyl groups,        or a group SO₂NH—(C₁-C₆)alkyl or SO₂NH₂,    -   R₄₃ and R₄₄, independently of each other, represent a hydrogen        atom, a halogen atom, a linear or branched C₁-C₆ alkyl group, a        C₁-C₆ alkoxy group, a nitro, cyano, CONH₂, SO₂NH(C₁-C₆)alkyl,        SO₂NH₂, SO₃H or SO₃Na group or a C₆-C₁₂ aryl group, which is        unsubstituted or substituted with one or more halogen atoms, one        or more linear or branched C₁-C₆ alkyl, nitro, acetyl or        SO₂NH(C₁-C₆)alkyl groups or with SO₂NH₂,    -   R₄₅ and R₄₆ represent, independently of each other, a hydrogen        atom, a halogen atom, a C₁-C₆ alkoxy group or a nitro, cyano,        hydroxyl or amino group,    -   the azomethine derivatives of formula (XXXI)

-   -   R₄₇, R₄₈, R₄₉ and R₅₀, independently of each other, represent a        hydrogen atom, a halogen atom, a linear or branched C₁-C₆ alkyl        group, a C₁-C₆ alkoxy group, a nitro, cyano, CONH₂,        SO₂NH—(C₁-C₆)alkyl, SO₂NH₂, SO₃H or SO₃Na group or a C₆-C₁₂ aryl        group, which is unsubstituted or substituted with one or more        halogen atoms, one or more linear or branched C₁-C₆ alkyl,        nitro, acetyl or SO₂NH(C₁-C₆)alkyl groups or with SO₂NH₂.

The cosmetic compositions in accordance with the invention contain atleast one latent pigment and at least one compound chosen fromacidifying agents, surfactants, monoalcohols and polyols that are liquidat 25° C.

The acidifying agents in the compositions of the invention may bemineral or organic. In the latter case, the functions providing theacidity may be sulphonic or carboxylic groups. As acidifying agents thatmay be used according to the invention, mention may be made ofhydrochloric acid, citric acid, lactic acid and tartaric acid.

The concentration of acidifying agents may range from 0.0001% to 20% andpreferably from 0.01% to 10% of the total weight of the compositions.

The monoalcohols or polyols that are liquid at 25° C. in thecompositions according to the invention are saturated or unsaturated.They are preferably chosen from ethanol, isopropanol, propylene glycol,glycerol, hexylene glycol, isoprene glycol, dipropylene glycol,neopentyl glycol, 3-methyl-1,3,5-pentanetriol, 1,2,4-butanediol,1,5-pentanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol,polyethylene glycols and benzyl alcohol.

Their concentration may be between 0.05% and 50% and preferably between0.1% and 20% of the total weight of the composition.

The surfactants may be of anionic, nonionic, cationic or amphotericnature. The surfactants that are suitable for use in the presentinvention are especially the following:

-   -   (i) Anionic surfactant(s):

By way of example of anionic surfactants that can be used, alone or asmixtures, in the context of the present invention, mention may be madein particular (nonlimiting list) of salts (in particular alkali metalsalts, especially sodium salts, ammonium salts, amine salts, aminoalcohol salts or magnesium salts) of the following compounds: alkylsulphates, alkyl ether sulphates, alkylamido ether sulphates, alkylarylpolyether sulphates, monoglyceride sulphates; alkyl sulphonates, alkylphosphates, alkylamide sulphonates, alkylaryl sulphonates, α-olefinsulphonates, paraffin sulphonates; (C₆-C₂₄)alkyl sulphosuccinates,(C₆-C₂₄)alkyl ether sulphosuccinates, (C₆-C₂₄)alkylamidesulphosuccinates; (C₆-C₂₄)alkyl sulphoacetates; (C₆-C₂₄)acylsarcosinates and (C₆-C₂₄)acyl glutamates. It is also possible to use(C₆-C₂₄)alkylpolyglycoside carboxylic esters such as alkylglucosidecitrates, alkylpolygiycoside tartrates and alkylpolyglycosidesulphosuccinates, alkylsulphosuccinamates; acyl isethionates and N-acyltaurates, the alkyl or acyl radical of all of these different compoundspreferably containing from 12 to 20 carbon atoms and the aryl radicalpreferably denoting a phenyl or benzyl group. Among the anionicsurfactants which can also be used, mention may also be made of fattyacid salts such as oleic, ricinoleic, palmitic and stearic acid salts,coconut oil acid or hydrogenated coconut oil acid; acyl lactylates inwhich the acyl radical contains 8 to 20 carbon atoms. It is alsopossible to use alkyl D-galactosiduronic acids' and their salts,polyoxyalkylenated (C₆-C₂₄)alkyl ether carboxylic acids,polyoxyalkylenated (C₆-C₂₄)alkylaryl ether carboxylic acids,polyoxyalkylenated (C₆-C₂₄)alkylamido ether carboxylic acids and theirsalts, in particular those containing from 2 to 50 alkylene oxidegroups, in particular ethylene oxide groups, and mixtures thereof.

-   -   (ii) Nonionic surfactant(s):

The nonionic surfactants are, themselves also, compounds that are wellknown per se (see in particular in this respect “Handbook ofSurfactants” by M. R. Porter, published by Blackie & Son (Glasgow andLondon), 1991, pp. 116-178) and their nature is not a critical factor inthe context of the present invention. Thus, they can be chosen inparticular from (nonlimiting list) polyethoxylated or polypropoxylatedalkylphenols, alpha-diols or alcohols, having a fatty chain containing,for example, 8 to 18 carbon atoms, it being possible for the number ofethylene oxide or propylene oxide groups to range in particular from 2to 50. Mention may also be made of copolymers of ethylene oxide and ofpropylene oxide, condensates of ethylene oxide and of propylene oxidewith fatty alcohols; polyethoxylated fatty amides preferably having from2 to 30 mol of ethylene oxide, polyglycerolated fatty amides containingon average 1 to 5, and in particular 1.5 to 4, glycerol groups;oxyethylenated fatty acid esters of sorbitan having from 2 to 30 mol ofethylene oxide; fatty acid esters of sucrose, fatty acid esters ofpolyethylene glycol, alkylpolyglycosides, N-alkylglucamine derivatives,and amine oxides such as (C₁₀-C₁₋₄)alkylamine oxides orN-acylaminopropylmorpholine oxides. It will be noted thatalkylpolyglycosides are nonionic surfactants that are particularlysuitable within the context of the present invention.

-   -   (iii) Amphoteric or zwitterionic surfactant(s):

The amphoteric or zwitterionic surfactants, the nature of which is not acritical factor in the context of the present invention, can be, inparticular (nonlimiting list), aliphatic secondary or tertiary aminederivatives in which the aliphatic radical is a linear or branched chaincontaining 8 to 18 carbon atoms and containing at least onewater-solubilizing anionic group (for example carboxylate, sulphonate,sulphate, phosphate or phosphonate); mention may also be made of(C₈-C₂₀)alkylbetaines, sulphobetaines,(C₈-C₂₀)alkylamido(C₁-C₆)alkylbetaines or(C₈-C₂₀)alkylamido(C₁-C₆)alkylsulphobetaines.

Among the amine derivatives, mention may be made of the products soldunder the name Miranol, as described in U.S. Pat. Nos. 2,528,378 and2,781,354 and classified in the CTFA dictionary, 3rd edition, 1982,under the names Amphocarboxyglycinates and Amphocarboxypropionates, withthe respective struetures:R₂—CONHCH₂CH₂—N(R₃)(R₄)(CH₂COO⁻)in which: R₂ denotes a linear or branched C₅-C₂₀ alkyl radical derivedfrom an acid R₂—COOH present, for example, in hydrolysed coconut oil, aheptyl, nonyl or undecyl radical, R₃ denotes a beta-hydroxyethyl groupand R₄ denotes a carboxymethyl group; andR₂′—CONHCH₂CH₂—N(B)(C)in which:

B represents —CH₂CH₂OX′, C represents —(CH₂)_(z)—Y′, with z=1 or 2,

X′ denotes the —CH₂CH₂—COOH group or a hydrogen atom,

Y′ denotes —COOH or the —CH₂—CHOH—SO₃H radical,

R₂′ denotes a saturated or unsaturated, linear or branched C₅-C₂₀ alkylradical of an acid R′₁₂—COOH present for example in coconut oil or inhydrolysed linseed oil, an alkyl radical, in particular a C₇, C₉, C₁₁ orC₁₃ alkyl radical, a C₁₇ alkyl radical and its iso form, or anunsaturated C₁₇ alkyl radical.

These compounds are classified in the CTFA dictionary, 5th edition,1993, under the names Disodium Cocoamphodiacetate, DisodiumLauroamphodiacetate, Disodium Caprylamphodiacetate, DisodiumCapryloamphodiacetate, Disodium Cocoamphodipropionate, DisodiumLauroamphodipropionate, Disodium Caprylamphodipropionate, DisodiumCapryloamphodipropionate, Lauroamphodipropionic acid andCocoamphodipropionic acid.

By way of example, mention may be made of the cocoamphodiacetate soldunder the trade name Miranol® C2M Concentrate by the company RhodiaChimie.

-   -   (iv) Cationic surfactants:

Among the cationic surfactants, mention may be made in particular(nonlimiting list) of: salts of optionally polyoxyalkylenated primary,secondary or tertiary fatty amines; quaternary ammonium salts such astetraalkylammonium, alkylamidoalkyltrialkylammonium,trialkylbenzylammonium, trialkylhydroxyalkylammonium or alkylpyridiniumchlorides or bromides; imidazoline derivatives; or amine oxides ofcationic nature.

Their concentration may be between 0.05% and 50% and preferably between0.2% and 25% of the total weight of the composition.

The medium that is suitable for dyeing, also known as the dye support,is preferably an aqueous medium containing at least one of the aboveingredients.

Preferably, the compositions according to the invention have a pH of <7.

Standard cosmetic adjuvants used in dye compositions, such asantioxidants, penetrating agents, sequestering agents, fragrances,buffers, dispersants, film-forming agents, ceramides, preserving agents,opacifiers, vitamins or provitamins, nonionic, cationic, anionic oramphoteric polymers, and associative or non-associative mineral ororganic thickeners, may be used in the compositions.

Needless to say, a person skilled in the art will take care to selectthis or these optional additional compound(s) such that the advantageousproperties intrinsically associated with the dye composition inaccordance with the invention are not, or are not substantially,adversely affected by the envisaged addition(s).

Another subject of the invention relates to a process for dyeing keratinfibres, in particular human keratin fibres and more particularly thehair, using latent pigments.

In a first stage, a composition containing, in a medium that is suitablefor dyeing, at least one latent pigment used according to the inventionis applied to the keratin fibres.

The dye composition is left to act for a leave-in time ranging from 1 to60 minutes and preferably from 10 to 45 minutes.

The fibres are then optionally rinsed.

The latent pigment on the said fibres is then treated thermally,chemically or photochemically so as to regenerate the sparingly solubleoriginal compound. Preferably, the latter treatment is performed bymeans of a jump in pH. The solution used makes it possible to achieve apH of greater than 7. An aqueous ammonia, alkanolamine, alkalinehydroxide or alkaline carbonate solution may be used.

Finally, steps of washing with shampoo and drying are performed.

The invention also relates to a two-compartment device for dyeing thefibres. The first compartment of this device contains a dye compositioncontaining, in a medium that is suitable for dyeing, at least one latentpigment used according to the invention, and the second compartmentcontains a solution of a chemical agent capable of rendering insolublethe latent pigment as the sparingly soluble original compound. Thesecond compartment will preferably contain a solution for achieving a pHof greater than 7.

The example that follows is intended to illustrate the invention withoutbeing limiting in nature.

EXAMPLE

The Applicant prepared a composition containing compound A shown below.

The composition containing compound A was formulated as follows:

Dye formulation Natrosol 250MR (hydroxyethylcellulose) 0.72 g NIPA ester82121 (mixture of methyl, butyl, ethyl, propyl 0.06 g and isobutylp-hydroxybenzoates) Oramix CG 110 ((50/50 C8/C10) alkyl polyglucoside(2)   5 g as a buffered aqueous 60% solution) Benzyl alcohol   4 gPolyethylene glycol 400 (polyethylene glycol (8 EO))   6 g Compound A 0.3 g Citric acid qs pH 4 Water qs

The composition was applied to lightly bleached hair with a bath ratioof 10.

After a leave-in time of 30 minutes, a dilute triethanolamine solutionwas applied to the lock. The regeneration reaction was thus performed bymeans of a jump in pH. The colour of the lock then changed from violetto blue.

The lock was then shampooed and dried. It was blue and the colorationshowed a very good level of fastness.

1. A process for dyeing human keratin fibers, comprising applying to thekeratin fibers a composition comprising at least one latent pigment,wherein said at least one latent pigment is soluble in a medium that issuitable for dyeing, and then chemically, thermally or photochemicallyconverting the latent pigment in the keratin fibres into awater-insoluble pigment wherein the at least one latent pigment ischosen from those of formula (I):A(B)x  (I) wherein: x is an integer ranging from 1 to 8, A is thechromophoric radical of dyes comprising a hetero atom chosen from N, Oand S, wherein when x is equal to 1, B is chosen from groups of formula(II), when x is greater than 1, B is chosen from a hydrogen atom andgroups of formula (II), with the proviso that when x is greater than 1,B is at least once a group of formula (II):

wherein Z is chosen from cationic water-solubilizing groups Z⁺ andpolyethylene glycol residues, Y is a hetero atom chosen from N, O and S,F and F′ which can be identical or different, are chosen from linear andbranched C₁-C₁₄ alkylene chains, which can optionally comprise heteroatoms and can optionally be substituted with at least one entity chosenfrom hydroxyl radicals, amino radicals, and halogens, n, m and m′, whichmay be identical or different are chosen from zero and 1, and B islinked to a hetero atom of the chromophore A.
 2. The process accordingto claim 1, wherein the human keratin fibers are hair.
 3. The processaccording to claim 1, wherein Y is oxygen.
 4. The process according toclaim 1, wherein Z⁺ is chosen from aliphatic groups, aromatic groups,saturated and unsaturated carbocyclic groups and heterocyclic groups,and wherein Z⁺ bears at least one quaternized nitrogen atom.
 5. Theprocess according to claim 1, wherein the chromophoric radical A is anazo dye radical.
 6. The process according to claim 5, wherein the azoradicals are chosen from the compounds of formulae (XXIII) to (XXVIII):

wherein R₃₃, R₃₄, R₃₅, B₃₆, R₃₇, R₃₈ and R₄₀, which may be identical ordifferent, are chosen from hydrogen atoms, halogens, linear and branchedC₁-C₆ alkyl groups, C₁-C₆ alkoxy groups, nitro groups, acetyl groups,and SO₂NH(C₁-C₆)alkyl groups, R₃₉ is chosen from a hydrogen atom,halogens, linear and branched C₁-C₆ alkyl groups and C₁-C₆ alkoxygroups, and B is chosen from a hydrogen atom and groups of formula (II),with the proviso that at least one B per formula is a group of formula(II).
 7. A process for dyeing human keratin fibers, comprising: (i)applying to the keratin fibers a composition comprising, in a mediumthat is suitable for dyeing, at least one latent pigment, wherein the atleast one latent pigment is soluble in a medium that is suitable fordyeing, and is capable of being chemically, thermally or photochemicallyconverted in the keratin fibers into water-insoluble pigments, (ii)leaving the dye composition to act on the keratin fibers for a leave-intime ranging from 1 to 60 minutes, (iii) optionally rinsing the hair,and then converting the at least one latent pigment to an at least onewater-insoluble pigment in a manner chosen from thermal, chemical andphotochemical treatment, (iv) washing the treated fibers with shampoo,and drying wherein the at least one latent pigment is chosen from thoseof formula (I):A(B)x  (I) wherein: x is an iliteger ranging from 1 to 8, A is thechromophoric radical of dyes comprising a hetero atom chosen from N, Oand S, wherein when x is equal to 1, B is chosen from groups of formula(II), when x is greater than 1, B is chosen from a hydrogen atom andgroups of formula (II), with the proviso that when x is greater than I,B is at least once a group of formula (II):

wherein Z is chosen from cationic water-solubilizing groups Z⁺ andpolyethylene glycol residues, Y is a hetero atom chosen from N, O and S,F and F′, which can be identical or different, are chosen from linearand branched C₁-C₁₄ alkylene chains, which can optionally comprisehetero atoms and can optionally be substituted with at least one entitychosen from hydroxyl radicals, amino radicals, and halogens, n, m andm′, which may be identical or different are chosen from zero and 1, andB is linked to a hetero atom of the chromophore A.
 8. The process fordyeing keratin fibers according to claim 7, wherein the human keratinfibers are hair.
 9. The process for dyeing keratin fibers according toclaim 7, wherein the leave-in time ranges from 10 to 45 minutes.
 10. Theprocess for dyeing keratin fibers according to claim 7, wherein the atleast one latent pigment is chemically converted to at least onewater-insoluble pigment via an increase in pH.
 11. The process accordingto claim 10, wherein the at least one latent pigment in the keratinfibers is treated with a solution of an alkaline compound.
 12. Theprocess according to claim 11, wherein the alkaline compound is chosenfrom aqueous ammonia, alkanolamines, alkaline hydroxides and alkalinecarbonates.
 13. A cosmetic composition for dyeing human keratin fiberscomprising at least one latent pigment, at least one compound chosenfrom monoalcohols and polyols that are liquid at 25° C. and surfactants,and at least one acidifying agent chosen from mineral and organicacidifying agents, wherein the at least one latent pigment is capable ofbeing chemically, thermally or photochemically converted in the keratinfibers into an at least one water-insoluble pigment wherein the at leastone latent pigment is chosen from those of formula (I):A(B)x  (I) wherein: x is an integer ranging from 1 to 8, A is thechromophoric radical of dyes comprising a hetero atom chosen from N, Oand S, wherein when x is equal to 1, B is chosen from groups of formula(II), when x is greater than 1, B is chosen from a hydrogen atom andgroups of formula (II), with the proviso that when x is greater than 1,B is at least once a group of formula (II):

wherein Z is chosen from cationic water-solubilizing groups Z⁺ andpolyethylene glycol residues, Y is a hotero atom chosen from N, O and S,F and F′, which can be identical or different, are chosen from linearand branched C₁-C₁₄ alkylene chains, which can optionally comprisehetero atoms and can optionally be substituted with at least one entitychosen from hydroxyl radicals, amino radicals, and halogens, n, m andm′, which may be identical or different are chosen from zero and 1, andB is linked to a hetero atom of the chromophore A.
 14. The compositionaccording to claim 13, wherein Y is oxygen.
 15. The compositionaccording to claim 13, wherein Z⁺ is chosen from aliphatic groups,aromatic groups, saturated and unsaturated carbocyclic groups andheterocyclic groups, and wherein Z⁺ bears at least one quaternizednitrogen atom.
 16. The composition according to claim 13, wherein thechromophoric radical A is an azo dye radical.
 17. The compositionaccording to claim 13, wherein the surfactants are chosen from nonionic,anionic, cationic and amphoteric surfactants.
 18. The compositionaccording to claim 13, wherein the at least one compound is chosen fromacidifying agents and is present in the composition in an amount rangingfrom 0.0001% to 20% by weight, relative to the total weight of thecomposition.
 19. The composition according to claim 18, wherein the atleast one acidifying agent is present in the composition in an amountranging from 0.01% to 10% by weight, relative to the total weight of thecomposition.
 20. The composition according to claim 13, wherein the atleast one compound is chosen from surtactants and is present in a totalamount ranging from 0.05% to 50% by weight, relative to the total weightof the composition.
 21. The composition according to claim 20, whereinthe at least one surfactant is present in a total amount ranging from0.1% to 20% by weight, relative to the total weight of the composition.22. The composition according to claim 13, wherein the at least onecompound is chosen from monoalcohols and polyols that are liquid at 25°C. and is present in a total amount ranging from 0.05% to 50% by weight,relative to the total weight of the composition.
 23. The compositionaccording to claim 22, wherein the at least one compound is present in atotal amount ranging from 0.1% to 20% by weight, relative to the totalweight of the composition.
 24. The composition according to claim 13,wherein its pH is less than
 7. 25. A kit for dyeing human keratinfibres, comprising at least two compartments, wherein the at least onefirst compartment comprises a dye composition comprising, in a mediumthat is suitable for dyeing, at least one latent pigment and at leastone compound chosen from monoalcohols and polyols that are liquid at 25°C., acidifying agents and surf actants, wherein the at least one latentpigment is capable of being chemically, thermally or photochemicallyconverted in the keratin fibres into an at least one water-insolublepigment; and wherein the at least one second compartment comprises adilute solution of a chemical agent capable of rendering the at leastone latent pigment insoluble wherein the at least one latent pigment ischosen from those of formula (I):A(B)x  (I) wherein: x is an integer ranging from 1 to 8, A is thechromophoric radical of dyes comprising a hetero atom chosen from N, Oand S, wherein when x is equal to 1, B is chosen from groups of formula(II), when x is greater than 1, B is chosen from a hydrogen atom andgroups of formula (II), with the proviso that when x is greater than 1,B is at least once a group of formula (II):

wherein Z is chosen from cationic water-solubilizing groups Z⁺ andpolyethylene glycol residues, Y is a hetero atom chosen from N, O and S,F and F′, which can be identical or different, are chosen from linearand branched C₁-C₁₄ alkylene chains, which can optionally comprisehetero atoms and can optionally be substituted with at least one entitychosen from hydroxyl radicals, amino radicals, and halogens, n, m andm′, which may be identical or different are chosen from zero and 1, andB is linked to a hetero atom of the chromophore A.
 26. The kit fordyeing keratin fibers according to claim 25, wherein the human keratinfibers are hair.
 27. The kit according to claim 25, wherein the at leastone second compartment comprises a solution comprising at least onealkaline compound.
 28. The kit for dyeing keratin fibers according toclaim 25, wherein Y is oxygen.
 29. The kit for dyeing keratin fibersaccording to claim 25, wherein Z⁺ is chosen from aliphatic groups,aromatic groups, saturated and unsaturated carbocyclic groups andheterocyclic groups, and wherein Z⁺ bears at least one quaternizednitrogen atom.
 30. The kit for dyeing keratin fibers according to claim25, wherein chromophoric radical A is an azo dye radical.